import { Injectable, Inject, HttpException } from '@nestjs/common';
import axios, { AxiosResponse, Method } from 'axios';
import { DadosferaLogger } from '@dadosfera/dadosfera-logs';

import { RequestUser } from '../../decorators/user.decorator';
import { STORAGE_EXPLORER_CONFIG } from './storage-explorer.config';

@Injectable()
export class StorageExplorerService {
  private logger: any;

  constructor(
    @Inject(DadosferaLogger) dadosferaLogger: DadosferaLogger,
  ) {
    this.logger = dadosferaLogger.logger;
  }

  async proxy(
    method: string,
    path: string,
    user: RequestUser,
    body?: any,
    query?: Record<string, any>
  ): Promise<any> {
    // Validate customer_id is present for multi-tenant isolation
    if (!user.customer_id) {
      throw new HttpException('Customer ID is required for storage operations', 400);
    }

    // Get customer-specific storage-explorer URL
    const baseUrl = STORAGE_EXPLORER_CONFIG.getUrl(user.customer_name);
    const url = new URL(`${baseUrl}${path}`);

    // Add query params
    if (query) {
      Object.entries(query).forEach(([key, value]) => {
        if (value !== undefined && value !== null) {
          url.searchParams.set(key, String(value));
        }
      });
    }

    const headers: Record<string, string> = {
      'content-type': 'application/json',
    };

    this.logger.info('Proxying request to storage-explorer', {
      method: method.toUpperCase(),
      path,
      customer_id: user.customer_id,
      storage_url: baseUrl,
      user_id: user.user_id,
    });

    try {
      const response: AxiosResponse = await axios({
        method: method as Method,
        url: url.href,
        headers,
        data: body,
        timeout: STORAGE_EXPLORER_CONFIG.timeout,
        validateStatus: () => true, // Don't throw on non-2xx
      });

      // Propagate non-2xx responses as HttpExceptions
      if (response.status >= 400) {
        throw new HttpException(response.data, response.status);
      }

      return response.data;
    } catch (error) {
      this.logger.error('Storage Explorer API proxy error', {
        error: error.message,
        status: error.response?.status,
        path,
        storage_url: baseUrl,
        method: method.toUpperCase(),
      });

      if (error instanceof HttpException) {
        throw error;
      }

      if (error.response) {
        throw new HttpException(error.response.data, error.response.status);
      }

      if (error.code === 'ECONNREFUSED') {
        throw new HttpException('Storage Explorer API service unavailable', 503);
      }

      if (error.code === 'ETIMEDOUT' || error.code === 'ECONNABORTED') {
        throw new HttpException('Storage Explorer API request timeout', 504);
      }

      throw new HttpException('Internal server error', 500);
    }
  }

  /**
   * Proxy with file upload support (multipart/form-data)
   */
  async proxyFormData(
    method: string,
    path: string,
    user: RequestUser,
    formData: any,
    query?: Record<string, any>,
  ): Promise<any> {
    // Validate customer_id is present for multi-tenant isolation
    if (!user.customer_id) {
      throw new HttpException('Customer ID is required for storage operations', 400);
    }

    // Get customer-specific storage-explorer URL
    const baseUrl = STORAGE_EXPLORER_CONFIG.getUrl(user.customer_name);
    const url = new URL(`${baseUrl}${path}`);

    // Add query params
    if (query) {
      Object.entries(query).forEach(([key, value]) => {
        if (value !== undefined && value !== null) {
          url.searchParams.set(key, String(value));
        }
      });
    }

    const headers: Record<string, string> = {
      // Let axios set Content-Type for multipart/form-data with boundary
      ...formData.getHeaders?.(),
    };

    this.logger.info('Proxying form data request to storage-explorer', {
      method: method.toUpperCase(),
      path,
      customer_id: user.customer_id,
      storage_url: baseUrl,
      user_id: user.user_id,
    });

    try {
      const response: AxiosResponse = await axios({
        method: method as Method,
        url: url.href,
        headers,
        data: formData,
        timeout: STORAGE_EXPLORER_CONFIG.timeout,
        maxContentLength: Infinity,
        maxBodyLength: Infinity,
        validateStatus: () => true,
      });

      if (response.status >= 400) {
        throw new HttpException(response.data, response.status);
      }

      return response.data;
    } catch (error) {
      this.logger.error('Storage Explorer API form data proxy error', {
        error: error.message,
        status: error.response?.status,
        path,
        storage_url: baseUrl,
        method: method.toUpperCase(),
      });

      if (error instanceof HttpException) {
        throw error;
      }

      if (error.response) {
        throw new HttpException(error.response.data, error.response.status);
      }

      throw new HttpException('Internal server error', 500);
    }
  }
}